I know what you mean. Iwill take several shots with different colored construction paper and I have a big sheet of cork I like. I read an article once that said to take a big plastic milk jug and cut it in half. Put a light either on top or behind for a nice effect. Haven't tried it yet, but it looks good on paper
I am sure you already know, but I will ask anyway. Do you use a tripod and do you push the shutter button slightly to focus?